Bevel or miter gearing.



No. 670,386. v Patented Mar. 19,. 19m. 1

C. H; HOWLAND-SHERMAN.

BEVEL 0B MITER GEARING.

(Application filed June 28,1900. (No Model.) 3 Sheets-8heet 2,

' H5 w I N i I. I R I: 11

NITED STATES ATENT FFICE."

CHARLES H. HOWLAND-SHERMAN,OF PATHFINDER, DISTRICT OF COLUMBIA, ASSIGNOROF ONE-FOURTH TO GEORGE H. HOWARD, OF WASHINGTON, DISTRICT OF COLUMBIA,AND SAMUEL G. B. COOK, OF LONDON, ENGLAND.

BEVEL OR MITER GEARING.

' SPECIFICATION forming part of Letters Patent No. 670,386, dated March19, 1901.

Application filed June 28, 1900- To all? whom it may concern:

Be it known that I, CHARLES H. HOWLAND- SHERMAN, a citizen of the UnitedStates, residing at Pathfinder, in the District of Colum- 5 bia, haveinvented a new and usefullmprovement in Bevel or Miter Gearing, of whichthe following is a specification, reference being had tothe'accompanying drawings and to the letters of reference markedthereon.

My invention relates to assembled bevel or miter gearing, having for itsobject to provide an economical bevel or miter structure susceptible ofready assembly upon an operative shaft and possessing greater strengththan would be attainable by casting the gear in a single piece, while atthe same time rendering practicable the substitution of new teeth upon ahub whose service is substantially indefinite in a manner easilyunderstood by mechanics. I attain this object by the mechanismillustrated in the accompanying drawings, hereby made a part of thisspecification, in which Figure 1 is a front elevation of a bevel-gearmade in accordance with my invention, showing the trifurcated toothedperiphery. Fig. 2 is a section on the line 2 2 of Fig. 1 through thecomplete assembled gear. Fig. 3 is a rear elevation of the gear with aportion of the hub broken away to show the interior formation of thetooth-segments. Fig. 4 is a section on theline 4 4 of Fig. 3 through thetoothsegments in assembled position with the hub removed to more clearlyexhibit the interior structure of the segments. Fig. 5 is a frontelevation of the complete hub with the toothsegments removed to show thehub details. Fig. '6 is a section through the hub alone on the line 6 bof Fig. 5, exhibiting the details of its webs and flanges.

Similar letters of reference indicate similar parts throughout theseveral views.

The hub H engages with the gear-shaft by means of any suitable keydriven in a key- 5 way K of the usual type, as indicated in Figs.

2, 5, and 6.

The hub H, Figs. 2, 5, and 6, is preferably cast as an integral memberand has, preferably integral therewith, webs w to, having Serial No.21,956- (No model.)

fiangesff, as particularly shown in Figs. 5 and 6, both of said webs andsaid flanges preferably running continuously around the hub. In gears ofrelatively small pitch diameter, such as that chosen for illustration inthe accompanying drawings, the front end the webs w to, sustaining theflanges ff.

This method of sustaining the web-and-flange structure gives perfectadaptability to all pitch diameters, as well as enabling theconstruction of gears of pitch diameters proportionately smaller inrelation to the gear-shaft than would be feasible with a solidcast gear.The hub H also has upon its rear end, preferably cast integraltherewith, a collar 0 for laterally facing against'the collar of anypedestal or hanger which may be adjacent to the gear, said collar 0projecting suitably to pro tect the bolts b from contact with contiguousmachinery.

The tooth-segments T, Figs. 1,2, 3, and 4, are preferably three innumber, as shown in the drawings, for moderate-sized gears, but may be,of course, of other desired number for gears of larger pitch diameters.The teethz "may be cast integrally upon bases 25, having interiorcircumferential flanges t t t, adapted to engage the exteriorcircumferential flanges f ff of the hub H, as clearly shown in assemblyin Fig. 2 and in segmental structure in Fig. 4.

The tooth-segments T are prevented from rotating with relation to thehub H by the single shearof keys It, fixed in slots lc',through the websw, by tap-bolts I0 and firmly engage in registering slots it out throughthe flanges t of the tooth-segments T, as clearly shown in assembly inFig. 2 and partially indicated in structure in Figs. 4, 5, and 6. Thetoothsegments T are also fixed, both longitudinally and rotarily withrespect to the hub H,by capbolts 1), fitting in bores through the webs wand threaded into the flanges t of said segments, as clearly indicatedin Figs. 2 and 3. Clearances are preferably left between the fronttransaxial faces of the flanges f ff and the adjacent portions of thesegmentbase i in. order that the segment-flanges '6 25 &c., may be drawndirectly against the webs 1010 by the action of the cap-bolts Z) inassembling the segments to the hub and also for thenot less importantconsideration of requiring only said flanges i &c., and the front facesof said webs w, &c., to be finished for assembling the parts. Thisarrangement affords much economy in constructing the gear.

The shop practice of making this assembled bevel-gear is exceedinglysimple. The hub H is preferably cast as a single piece integral with allits webs and flanges after themannershown in Figs. 5 and 6 and is thenchucked and interiorly bored out to fit its shaft and has its webscleaned off to receive the flanges of the gear-segments at one operationon the lathe. The slotting out of the keyways and drilling for thecap-bolts then completes the hub. Similarly the tooth segments T arecast as single pieces integral with all their flanges and are cleanedoff at the ends to correct radial assembling faces. The completesegments for the entire gear are then chucked together after the mannerindicated in Fig. 4 and simultaneously cleaned off on the lathe to faceup against the webs and flanges of the hub at one operation. Thepositions for the cap-bolts b are then bored and tapped into the flangesf of the tooth-segments and the segments drawn home to position on thehub by the bolts 5, completing the gear, as shown in the several views.This entire process is very economical, as it requires no handfinishingwhatever, and the weight of the completed gear is no greater than thatof ordinary solid cast gears of the kind.

The operation of my invention requires little explanation. The manner inwhich the tooth-segments are applied to and removed from the hub havingbeen already indicated, the onlystructnre requiring explanation is theparticular function performed by the hubflanges ff with thecorresponding segmentflanges 25 i, &c. The hub-flanges have longitudinalpositions with respect to the face of the gear and radial thicknesseswith respect to their longitudinal positions, causing them to present acircumferential shear which is exactly proportionate to the progressiveincrease of the centrifugal bursting moments due to the increase of theradii at which the principal masses of the tooth-segments rotatereckoned from the centers of gravity of their moduli at points in saidmasses intersected by the planes of shear lying along the front faces ofthe webs w or referred to said webs, as w, as will be plainly evidentfrom Fig. 2. The effect of this is to secure the lightest possiblestructure at large factors of safety and with substantial security fromexplosiomsuch as might readily attend the rotation of lesscorrectly madegears at much less circumferential velocities than this gear is designedto withstand.

Having thus described my invention, I claim- 1. Combined in a bevel ormiter gear struc ture, a hub having flanged webs, tooth-segments havingbases, said bases being provided with flanges adapted to engage theflanged Webs of said hub, and means for se curing said parts inengagement substantially as set forth.

2. Combined in a bevel or miter gear structure, a hub having flangedwebs, tooth-segments having bases, said bases being provided withflanges adapted to engage the flanged webs of the hub, and means forlongitudinally fixing and assembling said toothsegments in engagementwith the flanged webs of the hub, substantially as set forth.

Combined in a bevel or miter gear structure, a hub having flanged Websintegral therewith, tooth-segments having bases, said bases beingprovided with integral flanges adapted to engage the flanged webs of thehub, keys for rotarily fixing said segments with relation to said hub,and means for longitudinally fixing and assembling said toothsegments inengagement with the flanged webs of the hub, substantially as set forth.

4:. Combined in a bevel or miter gear structure, a hub having flangedwebs integral therewith, tooth-segments having bases, said bases beingprovided with integral flanges adapted to engage the flanged webs of thesaid hub, and cap-bolts for rotarily and longitudinally fixing andassembling said segments with relation to said hub, substantially as setforth.

5. Combined in a bevel or miter gear structure, a hub having flangedwebs integral therewith, tooth-segments having bases, said bases beingprovided with integral flanges adapted to engage the flanged webs of,said hub, keys for rotarily fixing said segments with relation to saidhub, and cap-bolts for longitudinally and rotarily fixing and assemblingsaid segments to said hub, substantially as set forth.

In testimony whereof I hereunto set my hand and seal.

CHARLES ll. HOWLAND-SHERMAN.

Witnesses:

GEORGE H. HOWARD, O. B. BULL.

